#1. ok
#2. ok
#3. The angles sum to 180, so
If <I = 140, then <U+<T = 40
Since <U = <T, <T = 20
How did you ever get 60? 140+60 = 200, greater than 180, even without <U!

#4. False
They have two equal sides, but can vary wildly in shape. Since their angles need not be equal, they need not be congruent. Even if their two equal sides are the same, the vertex angle can be different, making them not congruent.